The grand finale came in Satya Nadella's press conference Thursday, where he announced Microsoft's Office for the iPad and conjured a vision of a "cloud for everyone and every device." Nadella made clear Microsoft wants to dominate the SaaS segment of the cloud, starting with clients distributed and administered from its Office 365 hub and ultimately embracing a new wave of devices not imagined yet.

What should we make of this fresh cloud explosion? Let's take the three cloud flavors in turn.

1. The rush to IaaS

No one is sure exactly what Cisco has in mind for its OpenStack intercloud, but the idea of offering specialized cloud infrastructure services to, say, the telecommunications industry among other verticals is intriguing. If SDN means the days of high-end, high-margin networking equipment are numbered, Cisco had better lay the groundwork for high-end, high-margin cloud services.

As for the dramatic Google and Amazon IaaS price reductions, they still won't convince enterprises to move big chunks of their existing infrastructure to the cloud wholesale. Large enterprises can't tolerate that sort of dependency, and migration to Google or Amazon doesn't absolve the customer from having to manage infrastructure, virtual though it may be. On the other hand, lower cost can only accelerate the usual enterprise IaaS activities: dev and test, disaster recovery, and more recently using IaaS as a platform for buidling customer-facing systems of engagement that need to change and scale quickly.

It's a different proposition for businesses just starting out. Who wants to make risky capital investments in infrastructure? Cheap cloud capacity makes the all-in cloud practical, and the enticement of Sustained Use Discounts makes it less likely new businesses will eventually migrate their cloud deployments back to local infrastructure. Expect Google's competitors to clone that pricing model soon.